SKF Cylindrical roller bearing

SKF single-row cylindrical roller bearings, open design, NUP 2304 ECP 20x52x21

Types NU, NJ, and NUP
Single-row SKF cylindrical roller bearings in basic design are manufactured in many different versions, distinguished by the arrangement of the flanges on the inner and outer rings. The most common designs are:
Design NU
Bearings of design NU have two fixed flanges on the outer ring and a flange-less inner ring. The bearings allow axial displacements between the shaft and housing in both directions.
Design NJ
Bearings of design NJ have two fixed flanges on the outer ring and one fixed flange on the inner ring. They can guide the shaft axially in one direction. Axial displacements of the shaft are only possible in one direction.
Design NUP
Bearings of design NUP have two fixed flanges on the outer ring as well as one fixed flange and one loose flange disc on the inner ring. The bearing secures the shaft axially in both directions and is thus suitable for fixed bearings.
Main dimensions: DIN 5412-1:2000 / DIN 616:2000 / ISO 15:1998

Permissible misalignment:
Bearing series 2, 3: 4°
Bearing series 22, 23: 3°

Suffixes:
EC Optimized internal design, more and/or larger rollers, as well as modified roller/flange contact
P Cage made of glass-fiber reinforced polyamide 66, roller-guided
J Window cage made of unhardened steel sheet, roller-guided
C3 Bearing clearance greater than normal
C4 Bearing clearance greater than C4.